Tracker RDO timing fix

Fix the tracker RDO time of flight correction to depend on the z position of the hits, not the distance from the origin. Also, add CL options to set a timing offset in the digitization step. Better would be to use the truth vertex position, but for now this will allow some samples to be fixed. Also, print some statistics about the digi times to help debugging.

assigned to @torrence

mentioned in commit 2899bc31

merged